Bacterial　infections　of　plants　are　widespread　and　highly　virulent,　causing　serious　economic　losses　in　agricultural　production　worldwide.　These　infections　become　particularly　prevalent　during　rainy　weather,　characterized　by　high　humidity　and　low　light　intensity　(about　2-10%　of　a　sunny　day).　Here　we　identified　a　class　of　photosensitizers　that　were　effective　in　inhibiting　plant　bacterial　infections　under　rainy　weather　with　dim　light.　One　of　these　compounds,　compound　1,　demonstrated　exceptional　efficacy　by　eliminating　more　than　4　logs　(99.99%)　of　either　Xanthomonas　perforans　or　Xanthomonas　citri　subsp.　citri　(Xcc)　strain　at　a　concentration　of　6.25　mu　M　under　rainy　weather　conditions　with　a　light　exposure　of　28.51　J/cm2.　For　Clavibacter　michiganensis　(Cm),　compound　1　demonstrated　a　comparable　bactericidal　effect　at　a　lower　concentration　of　3.13　mu　M.　Furthermore,　compound　1　was　effective　in　controlling　plant　leaf　infections　during　rainy　weather.　Moreover,　compound　1　exhibited　a　potent　inhibitory　effect　on　the　biofilms　pertinent　to　tomato　spot　disease　and　citrus　canker　under　natural　illumination　on　rainy　days.　Additionally,　compound　1　displayed　remarkable　resilience　to　rain-wash　on　plant　leaves,　retaining　41.20%　of　its　initial　concentration　following　exposure　to　three　simulated　rain　events.　These　findings　provide　a　new　strategy　for　plant　pathogen　disease　management　highlight　its　feasibility　even　during　rainy　weather.